Various forms of room heaters to be utilized in conjunction with a fireplace flue or to be provided with flue pipes independent of fireplace flues have been heretofore provided for use as space heaters and many are designed to burn various forms of solid fuel, such as wood and/or coal. However, many of these space or room heaters rely upon convection air and radiation to provide heat transfer from the heater to the interior of the room to be heated and are thus not as efficient as they might be if they were provided with structure operative to effect forced air circulation through the heater. In addition, many of these previously known room or space heaters experience a considerable waste of heat due to the unrestricted passage of flue gases upwardly from the fireboxes of the heaters outwardly through the flue pipes thereof. Accordingly, a need exists for a room or space heater utilizing forced ambient air for circulation through the heater and including structure whereby the maximum amount of heat may be extracted from the flue gases of the heater before they are ducted away from the latter through the flue pipe thereof.
Various forms of room and space heaters including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 3,085,564, 3,880,141, 3,981,292, 3,995,611, 4,008,704, 4,015,581, 4,026,264 and 4,050,441.